Electric heater.



UNITED STATES ria- TENT YOFFICE.

WEEDEN B. UNDERWOOD, or ROCHESTER, NEW YORK, AssIGNoR To WILMOT CASTLE COMPANY, or ROCHESTER, NEW YORK, A CORPORATION.

ELECTRIC HEATER.

his invention relates to electrical devices for heating -water, or other iiuids.

1`he object ci the invention is to produce all electric heater ofl a compact, durable and clicientfoIm, and particularly onein which the heating-'units may be subjected to a substantial mechanical pressure, whereby their parts are brought into close contact with each other and with the Walls of the chambers in which the fluid to be heated is conel ta1ned, thus promoting the rapid conduction of the heat, and at the same time preventing the attainment of an excessive temperature by the heating-elements.

To the foregoing end the invention inf volves various novel features of construction and rtrrangement hereinafter Aset forth'.

In the accompanying drawings Y Figure 1 is a. vertical median section of an electric heater embodying the present invention; 'l i Fig. 2 isV a front-elevation, with parts broken` away to show the interior construe tion;

Fig. 3 is an enlarged detai1viewshowng the coreand the heating-elements of 'one of the heating-units;

Fig. 4 isa cross-section of the heatingmnits; and

Fig. 5 1s a cross-section of a' complete heating-unit.

The invention is illustrated as embodied in a' heater comprising three castings or body-members 18, 19 and 20. The members 18 and 19 have inner walls 21and `22, and outer walls 23 and 24, respectively, the spaces 26 between these walls being adapted for the reception of the water w ich Is to '.be heated. The intermediate member 20 is formed with a similar water-space, andall of these spaces -V are connected, at top and bottom, by passages 27 and 28,` as shown particularly in Fig. 1, the passage 27 communicating with an inlet-pipe 29 for cold Water, while the passa e128 communicates with `an outlet-pipe 30' or the heated water, these pipes being threaded intothe front Specification ol Letters Patent.

B. UNDEE- sure above referred to Without injury Patented Teb. 13, 1917.

Application filed December 14, 1915. Serial QLD. 66,821.

bodyaneinber 18. Gaskets 3l are interposed between the 'adjacent surfac es of ,the bodymembers, around the openir gs forming the passages 27 and28, to pre 7ent leakage of' water at these points, and the body-mem 11ers are all tightly clamp ed together by means of through-bolts 32.

The heating-units H, which are of the usual flat, elongated form, are interposed between the adjacent surta( es of the bodymembers, the surfaces of tie intermediate member 2O being recessed, as shown in Fig.

l, to receive the units. This construction is such that when the part; are drawn together by thebolts 32 the heating-units are tightly clamped between tle adjacent surfaces', so that the heat from them is effec-l tively conducted through tie walls of the body-members, and thus 4lirectly to. lthe water inclosed between those Walls. The heated water rises betweer the walls and escapes through thepassage 28 and the pipeV 30,l` eing replaced by colt, water iowing into the pipe 29.

i l have devised a form of he lting-unit which is particularly adapted to sustain the pres- For this nirpose I employ, as shwn particularlyV in Figs. 3 and 4, a central co 'e in the form of. a thick strip 10 of mica, or other refractoryl material, the strip being provided wit ment, I employ two such dei ices, in the form I of narrow strips 11 and l2 of resistanceparts of one of metal. Each of these strips is wound in a modified helix'upon the co re 10, all of the stretches of the stripwll bei: 1g normal to the length of the core on the front of the core, as shown in Fig. l3, while o1 i` the-back of the core the stretches of the stri p 11 are inclined to the lengthiof the core, this disposition being secured by the use of 'the proper notches in winding the stri o. The strip 12,

on the other hand, is wc und so that its 100 stretches on the rear surfme of the core are normal to the length t iereof, and its stretches on the front of the core are inclined in the same direction as t 1e rear stretches of thestrip 11. From this disposition of the 105.

parts itresults that the stretches are arranged exiictly opposite e: ch other on the two sides of the core. Accordingly, when the parts are'subjectcd to p ressure this pressure is transmitted directly through the core 110 from strip to strip, and there is no tendency, therefore, to bend or shear the core, such as would occur in the ofl the usual helical arrangement of the heating-element.

Another feature of the invention resides in the means for connecting the heating-elements with the external source of current. For this purpose I employ, as is usual, a fiat conductive ribbon 13, but in accordance with the present invention the core is provided with. a, perforation 14, at some distance from its end, and the strip 13 is'pfissed through this perforation and then bent beek on both sides of the core. Its two portions may lie either inside or outside of the heating-elements: but in either ense 'it makes contact with several turns oit them on both sides 4of the core, and ut the sanne time its location in the periorution 141-. prevents it from being displaced in any dirertion relatively to the core or the heatingelements.

The l'ieutlng-unit is completed by supplying u1 sheet of' insuluting` material lli to either side of the ports shown in Fig. il. :1nd then enveloping the whole in iex'ble sheet-n|etul 17, :1s shown in Fig. i3.

The termin:1l-Conductors 13 are attuched to binding-posts 84, which are mounted on :t yoke 33 supported by lugs projecting from the body-members, as shown in Fig. 2,

Whenever it becomes necessary to replace or reunir one ef the heating-units, this may very readily be done upon removing the bolts 32, whereupon. the body-members may be taken apart and either of the units remov'edend replaced.

While the heater has been shown und de scribed as comprising three body-members, it. will be apparent that the number muy be indefinitely increased without any change in the general form or construction of these members, thus providing e heater of any desired capacity; :md in general, the invention is not limited to the' embodiment thereof hereinbefore described and illustrated in the accompanying drmvings, but may be ein* bodied in Various other forms, within the. nature of the invention as it is defined in the following claims 1. An electric heater comprising a pluralit)7 of se :irate hollow bodies each having n ehumland openings :it opposite ends vof the leiiamber7 said openingsproviding two continuous pussngewzrys et the ends of the henter, the' two passages being connected by the elnlmbers, und electrica-l heating units interposed between the hollow bodies oit pointeI between the two passngeways.

2. .An electric heater comprisingr a` plurulity oi selmrnle hollow bodies lying in abut ting' relation nud formed with chuinbers between them, ench body having nninternnl chamber and openings at opposite ends oft the chamber, said openings providing twoA continuous passegeweys at the ends of the heater, the two passsgeweys being connected by the internal chambers, and electric heeting units interposed inthe chambers between the hollow bodies.

VVE-EDEN B. UNDERWOOD. 

